Pneumatic action for musical instruments.



R. B. FOWLER. PNEUMATIC ACTION FOB. MUSICAL INSTRUMENTS. APPLICATIONFILED MAY 2, 1904.

Patented Mar. 4, 1913.

SSHEETS-SHEET L men 01 R. B. FOWLER.

PNEUMATIC AGTIODLPOB. MUSICAL INSTRUMENTS.

APPLICATION FILED MAY 2, 1904.

Patented Mar. 4, 1913.

, 5 SHEBTS-BHEET 2.

ITIUETI CC R. B. FOWLER. PNEUMATIC ACTION FOR MUSICAL INSTRUMENTS.

APPLICATI ON FILED MAY 2,1904. V Patented Mar. 4, 191d.

5 BEEBTBBHEET 3.

R. B. FOWLER PNEUMATIC ACTION FOR MUSICAL INSTRUMENTS.

APPLIOATION FILED MAY 2, 1904.

1,054,766 ?atented Mar.4,1913.

5 SHEETS-SHEET 4.

L'Uhllllll!IIUUUIJKIUNIILIWLIBUUUUUUUDUUUUUUIJUUUUUUUUUUUUUUUUUIIBUUUUUUUUU /Utne sses R. B. FOWLER.

PNEUMATIC ACTION FOR MUSIGAL INSTRUMENTS.

APPLICATION rum) MAY 2, 1904.

Patented ar. 4, 1913 5 SHEETS-SHEET 5.

. 26d G H Fig/11;

W nes ses Inwen 01" #301 D TOP 1%.

i much of a pneumatic action for musical ini resented by broken lines.

' a top view of, the accenting keys and per- .to valve RUFUS 'IB.FOWLER, 0F WORCES TED STATES PA TENT: OFFICE.

TER, MASSACHUSETTS.

PNEUMATIC ACTION FOR MUSICAL INSTRUMENTS.

Specification of Letters Patent.

Patented Mar. 4, 1 91' 3.

Application filedMay 2, 1904. Serial No. 205,877.

To all whom it may concern I Be it known that I, RI'FLS B Fownsn, acitizen of the United States, residing at Viorcesten in the county ofWorcester and Commonwealth of Massachusetts, have invented a new anduseful Improvement in Pneumatic Actions for Musical Instruments, ofwhich the following is a, specification, accompanied by drawings forminga part of the same, in which- Figure 1 represents an end view of sostruments as .is necessary to illustrate the character and mode ofoperation of my present invention with the inclosing case shown insectional View. Fig. 2 is a front view. Fig. 3 is a vertical sectionalview through that portion" of the action comprising the valve and motorpneumatics. Fig. 4 is a top view of a detached portion of the actionshowing the sliding valves for controlling air passages leading to thebellows. Fig. a sectional view on line Fig. 4, showing a front view ofan air passage with the position of the closing valve rep- Fig. 6 is asectional view of the ventchambers. Fig. 7 is forated music sheet. Fig.8 is a view of the upper ends of the key controlled pipes. Fig. 9 isatop view ofa portion of the accenting keys and rocking lever actuatedthereby for varying thefforce of an ac cented'note. Fig. 10 is a sideview of the suction bellows and connected wind chests, shown insectional view, and Fig. 11 is a view of the rear end of one of theaccenting keys with valves attached thereto.

Similar reference letters and figures refer to simiiar parts in thedifferent views. My present invention relates to a pneumatic mechanismemploying a perforated music sheet for actuating' a series of keystrikers for depressing ,thekeys of ajmusical instrument. such forexample as a piano, and the object of my inventionis to enable theoperator to control at will the force applied to any individual keystriker for the purpose of acce-nting any one or'more of the tonesproduced.

In the embodiment of my inyention I employ a perforated moving musicsheet for opening and closing the ducts of a tracker musical instrumentsboard, by which air is periodically admitted actuating pneumatics forthe purpose of controlling air passages between a 1 vacuum chamber andmotor pneumatics winch are operatlvely connected with the key strikersas The object of my present invention is to provide means by which' anyone of the tones sounded by the piano may be increased in force oraccented and I accomplish this result by providing an auxiliary vacuumchamber having a greater air exhaustion than the main vacuum chamber,and connected by a valve controlled air passage with each of the motorpneumatics, and providing means comprising a series of keys or is commonin that class of known as piano players.

manuals for cont-rolling said air passages at thewill of the operator.

By the mechanism hereinafter described thrt motor pneumatics areindividually connected with a main vacuum chamber by'the movement of theperforated music sheet over the tracker strikers to be individuallyoperated with a force (letermined'by the alr'exhaustion in" the mamvacuum chamber as in piano players now in use, but by the use of'aseries of keys .or manuals corresponding to the key strikers, I enablethe performer to connect atwvill anyone of the motor pneumatics with anauxiliary vacuum chamber, a greaterair Jexhaustion than the main vacuumchamber, so that the force of the board, causingthe key having keystriker actuated by said motor pneumatic will be increased and the tonesounded thereby accented.

In order to facilitate the accenting of desired tones I arrange a seriesof keys or manuals in the-instrument corresponding to keys of the pianowhich are acted upon by the key strikers, and I place upon or contiguousto each of the natural or white keys.

a letter to indicate the note corresponding to the tone of the piano ineach of the octaves, and I print upon the music sheet contiguous to theperforations of those notes which are to be accented, a letterindicating the ecu-responding tones of the piano, thereby enabling theoperator without any knowledge of music to correct-1y accent any of themarked notes by depressing the key in any particular octave marked witha letter corresponding to that upon the music sheet. v

In carrying out my invention I do not wish to confine myself strictly tothe minor details of construction as hereinafter set forth, but Ibelieve it to be broadly new in 'my invention, 2 and 3 denote musicrolls .from which a perforated music sheet 4 1s unwound from roll 2 andwound uponroll'3 during the operation of the mechanism, roll 3 beingrotated by a motor, not shown. which may be of any known form ofconstruction now employed in pneumatic ac tions of this class. 5 denotesa tracker board containing a series of ducts 6 which are closed by themusic sheet and are opened to the admission of air during the passage ofthe perforations over the ducts 6. Communicating with each of the ducts6 are pipes 7 leading to a series of valve pneumatics 8 by which valvecontrolled passages are opened and closed connecting motor pneumatics 9alternately with a vacuum chamber and with the outer air. The motorpneumatics 9 are operatively connected with levers 10 piv-- oted' atoneend to brackets 11 and having their free ends connected by links 12 withpivoted key strikers 13 which extend over eys14, 14 of a piano and arearranged tot depress the piano keys by the action of the. motorpneumatics 9 as the latter are controlled by the action of the valvepneumatics 8, said valvepneumatics 8 being in turn controlled by theopening and closing of the openings 6 in the tracker board by theperforated music sheet 4. By the operation of the valve pneumatics 8when air is admitted to the openings 6, the interior of the motorpneumatics 9 is closed to the outside air, and connected with vacuumchambers 15 from which air has been exl'ia'usted by any suitable means,such for example as a foot bellows, causing the motor pneumatics to becollapsed by the atmospheric pressure upon the outside, therebyactuating the key strikers 13 to depress the piano keys 11 with a forceproportioned to the amount of air ex haustion from the vacuum chambers15, and thereby causing av tone to bc souuded'pianis simo or fortissimoor with any intermediate force. The construction and arrangement of keystrikers 13 motor pneumatics 9, valve pneumatics 8, tracker board 5. andperforated music sheet -lare substantially the same as the comparableparts inpiano players now in use. i

The object of my present invention is to enable any one of the tonessoinded upon the piano to be accented at the will of the performer andindependently of the air exacted upon by a spring 23 to depress the endof the key and normally hold the valve 20 in contact with the open end19 of the air ipe 18 leading to the valve pneumatics 17.

Eor convenience in construction the vacuum chambers 15 and 16 arearranged one above the other in a vertical plane with their ed es incont-act thereby forming a support or each other and above the vacuumchambers 15 and 16 are placed two vent chambers 19 and 20"The-ventchamber 19 and vacuum chambers 15 are connected to andcommunicats with a vertical pipe 15 leading to an air chest.15" and thevent chamber 20" and vacuum chambers 16 are connected to and communicatewith, avertical pipe 16 leading to an air chest 16". i

he air chest-s 15 and 16" communicate with the opposite ends of a commonair chest 25 from which air is exhausted by a bellows 26, and operatedby a foot pedal 26 in the usual manner in instruments of this class. Theair exhaustion in the vent chanfr bcr 19 and vacuum chambers 15 will beuniform as they all communicate with a common pipe 15", and the airexhaustion in the vent chamber 20 and vacuum chambers 16 will also beuniform as they communicate with a common air pipe 16. The pipes 7leading from the tracker board to the primary pneumatics 8 will passthrou h the vent chamber 19 and are provide with vent holes 27. Fig; 6,to allow air to be'exhausted from the pipe 7 when the ducts of thetracker board are closed; The pipes 18 leading to the auxiliary valvepneumatics 1T likewise pass through the vent chamber 20 and are providedwith vent holes 28 to allow the pipes 18 to beexhausfted when their openends 19 are closed by the key valves 20. An

opening 29 between the air chest-s 15 and 25. Fig. 4, is controlled by asliding valve 30 having a valve' stem 31 connected 'with one end of alever, 82 pivoted at 33,-and having its opposite end connected by a link3t with a vertical lever 35, arranged to be operated by the performerto'control the size of the opening 29 and regulate the movement of airfrom the'air chest 15 into the air chest 25, and thereby controlithe airexhaustion in .the vacuum chambers 15 and vent chamber 19. The air chest16 communicates with the air chest 25 through an opening 86 whose 55.n'iotor pncimiatic.

Size is determined by a sliding valve 37 having a ,valve stem 38connected to one endof a lever 39 pivoted at 40 and connected at itsopposite end with a vertical lever 41 arranged tobe operated by theperformer and thereby control the air pressure in the vacuum chambers1t; and ventclmittber 20. The openings v 29 and 36 are normally closedby the valves 30 and. 37. which are 'held in their closed positions bysprings 42 and 43- and the communication between the air chests 16'means of an opening 4t having a sliding valved?) connected by a link 46with the hinged leaf of a regulating bellows 47. The bellows 47 isnormally held open by a spring 48 attached to the case of the machine.Air

is exhausted by the foot bellows :26 from the air chest 25 and alsothrough the opening 44 from the air chest 16", pipe 16. vacuum- 1chambers 16 and vent chamber-19. until the air exhaustion in the airchest. is sutl'icient to allow atmospheric pressure upon the regulatingbellows 47 to counteract the 25 tension of the spring 48 and close theopeninglet, by the sliding valve 45. The amount of air exhaustiontherefore fromthe vacuum chambers 16 and vent chamber 19 will bedetermined by the tension of the spring 48. The air chest 15 is likewiseprovided with ,a similar valvecontrolled opening 49. regulating bellows50 and spring 51 having a suitable tension to give'the desired air e.\'-haustion in the air chest 15 amt conse- 'quently in the vacuum chambers15 amt vent chamberitl I make the tension'ot' the spring 48 greater thanthe tension of the spring sothat the air exhaustion in the vacuumchambers 16 and vent chamber will be greater than the air exhaustionfrom the vacuum chambers 15 and vent. chamber, 19. If any one of themotor pneumatics 9 be'connect'cd with a vacuum chamber'16 instead of avacuum chamber 15. the

air exhaustion produced within the motor pneumatic will correspond withthe air exhaustion 'from the vacuum chamber lti and the force exerted bythe motor pneumatic through thelever 10. link 12. amt key striker 13will be correspomlingly increased over the force excited when said motorpneumatic is connected with a vacuum chamber 15, thereby accentingt'lietone produced by the particular key striker actuated by said Themethod of connecting at will a motor pneumatic with either a 'acuumchamber to or a vacuum chamber 15 is illustrated in the sectional iewshown in Fig, 3. Themotor.pneumatic E) 60 consists of a cup sha' 'it-dshell 52 having a flexiblediapl'u'agm 5!, on which is supportedal'ollowcr 5i conucctcd bv a link 53 'with the pivoted hncr it). Theililcl'iol rihanibcr 56 of thc motor pneumatic com- 65 inuni ates withan air spa e 57 in a horiand-25 is accomplished by thcreby sliding thezontal tube 58 from which the shell 52 is supported. The air space 57communicates with the outside air through an opening arranged to beclosed by a valve 60 carried on a valve stem 61, but normally held openby a spiral spring 62 so as to admit air to the chamber 56 of the motorpneumatic. The air space 57 is also connected with an air space (53 bymeans of an opening (it which is normally closed 1) a valve 65 carriedon the valve stem 61. The air space 63 is also connected with an airspace 66 through an opening 67 arranged to be opened and closed by acheck valve 68 capable of sliding on the valve stem (31. but having itsmovement. limited by the spurs (58. The air space 66 communicates withthe vacuum chamber 15' through openings (59 and is separated by aflexible diaphragm 70 from an air chamber 71. which is connected by .1pipe 7 with one of the openings 6 in the tracker board. Pressing againstthe diaphragm 71) by the tension of the spiral spring 62 is a follower72 in which is mounted the valve stem il. The air space 63 communicatesby an air passage 73 with an air space 74 which communicates by anopening 75 with an air space 76 communicating by an opening 77 with a'vacuum chamber 16. The air space To is separated by a flexible diaphragm78 from an air space it) which communicates with a pipe 18. the oppositeend of which is normally closed by a valve 20 attached toa pivoted key21. The opening 75 between the air spaces H amt To is normally closed bya alve 8O attached to. a valve stem 81 aml normally held against itsvalve seat by a spiral spring82. The valve stem 81 is mounted in afollower 83 which is held against the flexible diaphragm T8 by thetension of the spring 82;

The operation of the valve mechanism shown in Fig. 3 is as followshcnever a perforation in the musicsheet passes over an opening in thetracker board, air is admitted through the pipe 7 to an air space 71upon one side of the flexible diaphragm 70 and as a partial vacuumexists in the air space no on the opposite side oft-he flexiblediaphragm 7o owing to its communication with the vacuum chamber 15, fromwhich air has been exhausted by the bellows 26, the flexible diaphragmis moved to the right. valve stem (31 against tle tension oi the spiralspring (32, until the valve (it) has clcsed the opening 59, therebycutting otl thc connnunication between the chamber 5b of themotor-pncumatic and the outside air. -Simultaneously with the closing ofthe valve (it), thc valvc U5 is opened,

making a direct connnnnication between the chamber 5b oijthe motorpm-umatic and the vacuum chamber 15. into which air rushes from themotor pneumatic 9, allowing the diaphragm 53 to be raised by theatmosios - pushed to the right, 20 81 against the tension of the spiralspring l place upon the (I. r, j, and o, to denote the corresponding 5determined by the amount of air exhaustion fr: the vacuum chamber 15. Ifit is desired to accent a note sounded by the piano key when struck bythe key striker 13, one,

or" the keys 21, cor-res endingv to the piano key to be struck, isepressed by former, thereby lifting one of the valves and opening one ofthe pipes 18 through which air rushes to the air space 79 upon one sideof the lexible diaphragm 78, and as the airin the space 76 is partiallyexhausted by its communication through the opening 77 with thevacuum-chamber 16, the flexible diaphragm 78 will be at once sliding thevalve stem 82, and thereby opening a communication between the vacuumchamber 16 and the air space (33, and as the air exhaustion in thevacuum chamber 16 is greater -evhaustion in the vacuum chamber 15, thesliding check valve (38 will be moved on the valve stem (31 toward,theright,- thereby closing the opening 67 and preventing an inrush or airinto the air space 63 from the air 0 space illl,-'\l'lllll would tend toequalize the air pressure in the two vacuum chambers l5 and 16. Theconnnunicution is thus es tablished between the air space 63 and thevacuum chamber to by the depression of the key il just before theperforation in the paper corresponding to the tone to be sounded reachesa duct of the tracker board. When the perforation in the music sheetreaches the tracker board. air is admitted through the pipe I to the airspace 71, therebv sliding vthe valve stem bl to close the viilvc b0 andopen the valve when the air from the chamber as of the motor pneumaticwill rush through the opening lid upward through the air passage 73 andinto the vacuum chamber l thereby causing the key striker 1 3 to beactuated with a force corresponding to the air exhaustion in the vacuunichamber ll). it the keys are narrower than the keys of the piano, theopen ends it) oi the pipes i will slightly converge as shown in Fig. 8.In order to enable the proper keys it to be depressed by a perforun-runarrpiuintcd with the music played, keys Bl the letters (1,?2, 0,

notes of each octave as shown in Fig. 7, and at the l)0 llllllli10i eachperforation required to be accented l place a corresponding letter uponthe lllJSlJ sheet- -l as shown in Fig.

r. The lower letter 1' on said music sheet indicating that the keymarked a of the middle octave is to be depressed as the perforation 54 iapproaches one of the openings 6 in the tracker board. The next note atthe rightthe per than the air marked (Z sharp indicates that thecorresponding key in the middle octave is to be depressed as theperforation 85 approaches the opening 6 in the tracker board; In likemanner the toys of g sharp and a sharp of the middle octave are to bedepressed as the perforat ons 86 and 87 approach the tracker board", ndas the perforation 88 approaches the tracker board the key of 0 in thefirst octave above the middle is to be. depressed. If none of the keysare depressed during the movement of the perforated sheet over thetracker board, the key strikers will be actuated in the same manner asin pneumatic musical instruments of this class now in common use, andthe p1'oper key-strikers will be selected by the perforatidns of themusic sheet as it is moved over the tracker board, while theforceimparted to each striker can be controlled by the manipulation ofthe lever and valve 30, by which the communication between the airchests l5" and 25 can be varied by the performer independently of theregulating bellows 50; but whenever an additional force is required tobe given any individual key striker'in order to accent a tone, one ofthe keys 21 is depressed by the performer before the correspruidingpcrloration in the music sheet reaches the tracker board, and anydesired variation in the amount of accent or extra force in'iparted t0the key striker may be controlled by the performer through the lever 41and valve 37, thercby varying the communication between the air chests16*- and independently of the regulating bellows l7. I

interposed between the wind chests 15 and 1G and the wind chest areopenings 38 and 85h closed at will by sliding valves 90 and 91 havingtheir valve stems connected with hand levers, not shown, in order toallow the openings 88 and S9 to be closed; and entirely shut, oil allcommupication between toe vacuum tlltll-l lbtl'S l5 and 16" and the footbellows, which is required during the rentiruliugot the music sheet uponthe roll llcucuth the keys 21 is a bar 99, which 1 term a universal bar,attached at each end to the bent arms 93, which are pivoted at one endat l -l and connected at their free ends by links 95 and bell cranks 9Gwith the horizontally sliding bar 97. The bar 97 is provided with a spur98 arranged to contact with the lever 39, Fig. l. The bar 92 is arrangedto be depressed when any one of the keys 21 depressed, thereby slidingthe bar 97 toward the left as shown in Fig. 2 and rocking the lever 39to withdraw the valve 37. and increase the opening 56, there: byallowing the air to flow more freely from the wind chest 16'' into theWind chest and increasing the air exhaustion from the vacuum chambers 16and vent chamber wiiair exhaustion', by

- 3-; key strikers.

with aconsequent increase in the force 1 of the key-st'ri 21 r-whi'chhas been -depressed. "I am' aware that it has been proposed toaccentroiie or more of by the action of the keystrikers by the employment ot a motor pneumatic, which may beconnected at will with eitherone'of two .va cuuin:ehainbers havingditi'ering states of means of valvecontrolled ,;--ou t -regardto the position of the mark on r1 thesheet. 3I

v.1: IVhile I :contemplate the employment of ;,;as many. keys-or manualsas there are key .strikers .so that the force ot'each key striker in aybe controlled by its own corresponding 1 v,,I"do not wish to confinemyself to such nllSegtIS a lesser number may be employed if 5. desired;Neither; do I wish to confine my- I to the.u s e=of-asingle key-for eachof the .vfisclosing the ends of the air pipes 18, ;;36 ,3S, It .Wll l,be obvious that two or'more of i valves can be-attaehed to one key asnsh owniiin Fig. 11, where three of the valves 2Q are attached to a.single key 21. In the same iiiannerthe valves including an entire 40octave canbei ttached to and raised by a single key. i-\lthough it hasbeen proposed .to employ two vacuum chambers of differing airexhaustion, and to connect the motor to either by valve controlledpassages,

no means have been employed, so far as I am aware, to maintain a uniformair exhaustion on opposite sides of the valve operating diaphragms,while said diaphragins were notin action. I accomplish this bymaintaining two separate vent chambers in which the air exhaustion isthe same as the air exhaustion in the corresponding vacuum chambers. andby placing a check valve (38 between the vacuumchambers 15 and 16,

thereby preventing the equalizing of the air pressures in the two vacuumchambers, and

causing the. pipes 7 and 18 to vent into said vent chambers having thesame air exhaustion as the vacuum chambers 15 and 16. so

5 that the air pressure upon the opposite sides of the valve operatingdiaphragms. when the pipes T and 18 are closed. will always be the same.

Although I have shown and described a pneumatic inechanism in which amotor er corresponding to the key the tones produced l mechanisms andmeans for pneumatic for actuating a key striker is connected at willwitheither one of two vacuum chambers having differing degrees of airexhaustion. I do not confine myself to this construction and I do notclaim such an arrangement as new.

My present invention relates particularly to the employment of keys ormanuals arranged to be depressed at will by the per former, wherebycorresponding key strikers are actuated with an increased force, and Ihave illustrated this feature which, so far as .I am aware is broadlynew, in connection ving differing a convenient of individual with twovacuum chambersha degrees of air exhaustion as means of illustrating theuse keys or manuals corresponding with the key strikers for the purposenamed.

I have shown my invention as applied to a pneumatic mechanism adapted tooperate upon the keys of a musical instrument by means of motorpneumatics through the medium of pivoted levers or key strikers, but theemployment of a series of keys or manuals corresponding with the seriesof motor pneumatics. whereby each individual tone may be plicable to apneumatic the motor pneumatics mechanism in which ed with the noteproducing mechanism of.-

tlie instrument to be interior player.

\Vhat I claim as my invention and to secureby Letters Patentis 1. In amusical keyboard instrument. the combination with a series oftoneproducing actuating said tone producing mechanisms. "of means forvarying the force of said actuating mechaplayed. as in a so calleddesire -nisms with reference to each of said tone tively connected withproducing mechanisms individually and in-.

instrument operasaid force varying means.

2. In a musical keyboard instrument, a series of tone producingmechanisms, an actuating mechanism for each of said tone producingmechanisms. means for separately varying the actuating force of each ofsaid tone producing mechanisms. a series of keys or manualscorresponding with said tone producing mechanismsindividually connectedwith said separate force varying means.

3. The combination witha series of motor pneumatics corresponding withthe tones to be produced and means for actuating each of said motorpneumatics independently with ditt'crcnt degrees of force. of a seriesof keys or manuals corresponding to the keys of a keyboard instrumentfor indi vidually mntrolling'thc degree of force applied to eachactuating means.

accented at will. is equally apare directly connect with the keys of akeyboard instrument.

a single tone producing mechanism, means for applying difi'erent degreesof force to each automatic mechanism, means for determining the degreeof force to be applied to said automatic mechanism, and a separate keyor manual arranged to operate each force determinin means, said keys ormanuals arrange in series to correspond 6. The combination with a seriesof tone producing mechanisms, each arranged to produce a single tone,separate means for actuating each of said tone producing mechanisms withdifferent degrees of force independently of the other tone producingmechanisms, and means for connecting each of said tone producingmechanisms with its separate actuating mechanisms, comprising a seriesof keys or manuals corresponding with the keys or manuals of theinstrument. I

7. The combination ina keyboard musical instrument, with a series ofautomatic mechanisms each arranged to produce a single tone, means foractuating each of said tone producin mechanisms with different degreesof orce, and a separate key or manual operatively connected with each ofsaid actuatin means, with said keys or manuals arrange to correspondwith the keys or manuals of the instrument. I

8. The combination with a series of tone producing mechanisms, ofindividual automat-ic mechanisms for actuating each of said toneproducing mechanisms, with different degrees of force, means forconnecting said tone producing mechanisms with each of said actuatingmechanisms at will, comprising a key or manual corresponding to each ofsaid tone producing mechanisms.

'9. In a musical keyboard instrument, the combination with a series ofpneumatic mechanisms, each adapted to produce a single tone, of a seriesof separate vacuum chambers having different de rees of vacuum arrangedin pairs, means or connecting each of said pneumatic mechanismsalternately with veither vacuum chamber in said pairs of vacuunrchambersat will, comprising a key or manual corresponding to the in ividual toneproducing mechanism.

10. In a musical instrument, the combination of a tone producingmechanism, comprising a motor pneumatic, a main vacuum chamber, anauxiliary vacuum chamber, valve controlled passages connecting saidmotor pneumatic with each of said vacuum chambers, a kev'or manual forcontrolling the connection bet-ween said motor pneumatic and saidauxiliary vacuum chamber by the depression of the free end of said key,and means for restoring said key to its normal position.

11. In a musical instrument of the class described, the combination witha series of tone producing mechanisms, and means for actuating said toneproducing mechanisms, of a series of keys or manuals corresponding withsaid tone producing mechanisms connected with said actuating mechanismsand arranged to be depressed by the performer, whereby the force appliedto said tone producing mechanisms is varied.

RUFUS B. FOWLER.

\Vitnesses:

HENRY WOOD Fownaa, PENELOPE ConnnnnAcH.

